CPUs implementing mips32r2 may include a 64-bit FPU, just as mips64 CPUs
do. In order to preserve backwards compatibility a 64-bit FPU will act
like a 32-bit FPU (by accessing doubles from the least significant 32
bits of an even-odd pair of FP registers) when the Status.FR bit is
zero, again just like a mips64 CPU. The standard O32 ABI is defined
expecting a 32-bit FPU, however recent toolchains support use of a
64-bit FPU from an O32 mips32 executable. When an ELF executable is
built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF
header.
With this patch the kernel will check the EF_MIPS_FP64 flag when
executing an O32 binary, and set Status.FR accordingly. The addition
of O32 64-bit FP support lessens the opportunity for optimisation in
the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is
introduced to allow this support to be disabled for those that don't
require it.
Inspired by an earlier patch by Leonid Yegoshin, but implemented more
cleanly & correctly.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
arch/mips/Kconfig | 17 ++++++
arch/mips/include/asm/asmmacro-32.h | 42 --------------
arch/mips/include/asm/asmmacro-64.h | 96 --------------------------------
arch/mips/include/asm/asmmacro.h | 107 ++++++++++++++++++++++++++++++++++++
arch/mips/include/asm/elf.h | 17 +++++-
arch/mips/include/asm/fpu.h | 91 +++++++++++++++++++++++++-----
arch/mips/include/asm/thread_info.h | 4 +-
arch/mips/kernel/cpu-probe.c | 2 +-
arch/mips/kernel/process.c | 3 -
arch/mips/kernel/ptrace.c | 8 +--
arch/mips/kernel/ptrace32.c | 4 +-
arch/mips/kernel/r4k_fpu.S | 74 +++++++++++++++++++++++--
arch/mips/kernel/r4k_switch.S | 45 ++++++++++++++-
arch/mips/kernel/signal.c | 10 ++--
arch/mips/kernel/signal32.c | 10 ++--
arch/mips/kernel/traps.c | 20 +++++--
arch/mips/math-emu/cp1emu.c | 10 ++--
arch/mips/math-emu/kernel_linkage.c | 6 +-
18 files changed, 373 insertions(+), 193 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 17cc7ff..aa2e03a 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2335,6 +2335,23 @@ config CC_STACKPROTECTOR
This feature requires gcc version 4.2 or above.
+config MIPS_O32_FP64_SUPPORT
+ bool "Support for O32 binaries using 64-bit FP"
+ depends on (32BIT && CPU_MIPSR2) || MIPS32_O32
+ default y
+ help
+ When this is enabled, the kernel will support use of 64-bit floating
+ point registers with binaries using the O32 ABI along with the
+ EF_MIPS_FP64 ELF header flag (typically built with -mfp64). On
+ mips32 systems this support is at the cost of increasing the size
+ and complexity of the compiled FPU emulator. Thus if you are running
+ a mips32 system and know that none of your userland binaries will
+ require 64-bit floating point, you may wish to reduce the size of
+ your kernel & potentially improve FP emulation performance by saying
+ N here.
+
+ If unsure, say Y.
+
config USE_OF
bool
select OF
diff --git a/arch/mips/include/asm/asmmacro-32.h b/arch/mips/include/asm/asmmacro-32.h
index 2413afe..70e1f17 100644
--- a/arch/mips/include/asm/asmmacro-32.h
+++ b/arch/mips/include/asm/asmmacro-32.h
@@ -12,27 +12,6 @@
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
- .macro fpu_save_double thread status tmp1=t0
- cfc1 \tmp1, fcr31
- sdc1 $f0, THREAD_FPR0(\thread)
- sdc1 $f2, THREAD_FPR2(\thread)
- sdc1 $f4, THREAD_FPR4(\thread)
- sdc1 $f6, THREAD_FPR6(\thread)
- sdc1 $f8, THREAD_FPR8(\thread)
- sdc1 $f10, THREAD_FPR10(\thread)
- sdc1 $f12, THREAD_FPR12(\thread)
- sdc1 $f14, THREAD_FPR14(\thread)
- sdc1 $f16, THREAD_FPR16(\thread)
- sdc1 $f18, THREAD_FPR18(\thread)
- sdc1 $f20, THREAD_FPR20(\thread)
- sdc1 $f22, THREAD_FPR22(\thread)
- sdc1 $f24, THREAD_FPR24(\thread)
- sdc1 $f26, THREAD_FPR26(\thread)
- sdc1 $f28, THREAD_FPR28(\thread)
- sdc1 $f30, THREAD_FPR30(\thread)
- sw \tmp1, THREAD_FCR31(\thread)
- .endm
-
.macro fpu_save_single thread tmp=t0
cfc1 \tmp, fcr31
swc1 $f0, THREAD_FPR0(\thread)
@@ -70,27 +49,6 @@
sw \tmp, THREAD_FCR31(\thread)
.endm
- .macro fpu_restore_double thread status tmp=t0
- lw \tmp, THREAD_FCR31(\thread)
- ldc1 $f0, THREAD_FPR0(\thread)
- ldc1 $f2, THREAD_FPR2(\thread)
- ldc1 $f4, THREAD_FPR4(\thread)
- ldc1 $f6, THREAD_FPR6(\thread)
- ldc1 $f8, THREAD_FPR8(\thread)
- ldc1 $f10, THREAD_FPR10(\thread)
- ldc1 $f12, THREAD_FPR12(\thread)
- ldc1 $f14, THREAD_FPR14(\thread)
- ldc1 $f16, THREAD_FPR16(\thread)
- ldc1 $f18, THREAD_FPR18(\thread)
- ldc1 $f20, THREAD_FPR20(\thread)
- ldc1 $f22, THREAD_FPR22(\thread)
- ldc1 $f24, THREAD_FPR24(\thread)
- ldc1 $f26, THREAD_FPR26(\thread)
- ldc1 $f28, THREAD_FPR28(\thread)
- ldc1 $f30, THREAD_FPR30(\thread)
- ctc1 \tmp, fcr31
- .endm
-
.macro fpu_restore_single thread tmp=t0
lw \tmp, THREAD_FCR31(\thread)
lwc1 $f0, THREAD_FPR0(\thread)
diff --git a/arch/mips/include/asm/asmmacro-64.h b/arch/mips/include/asm/asmmacro-64.h
index 08a527d..38ea609 100644
--- a/arch/mips/include/asm/asmmacro-64.h
+++ b/arch/mips/include/asm/asmmacro-64.h
@@ -13,102 +13,6 @@
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
- .macro fpu_save_16even thread tmp=t0
- cfc1 \tmp, fcr31
- sdc1 $f0, THREAD_FPR0(\thread)
- sdc1 $f2, THREAD_FPR2(\thread)
- sdc1 $f4, THREAD_FPR4(\thread)
- sdc1 $f6, THREAD_FPR6(\thread)
- sdc1 $f8, THREAD_FPR8(\thread)
- sdc1 $f10, THREAD_FPR10(\thread)
- sdc1 $f12, THREAD_FPR12(\thread)
- sdc1 $f14, THREAD_FPR14(\thread)
- sdc1 $f16, THREAD_FPR16(\thread)
- sdc1 $f18, THREAD_FPR18(\thread)
- sdc1 $f20, THREAD_FPR20(\thread)
- sdc1 $f22, THREAD_FPR22(\thread)
- sdc1 $f24, THREAD_FPR24(\thread)
- sdc1 $f26, THREAD_FPR26(\thread)
- sdc1 $f28, THREAD_FPR28(\thread)
- sdc1 $f30, THREAD_FPR30(\thread)
- sw \tmp, THREAD_FCR31(\thread)
- .endm
-
- .macro fpu_save_16odd thread
- sdc1 $f1, THREAD_FPR1(\thread)
- sdc1 $f3, THREAD_FPR3(\thread)
- sdc1 $f5, THREAD_FPR5(\thread)
- sdc1 $f7, THREAD_FPR7(\thread)
- sdc1 $f9, THREAD_FPR9(\thread)
- sdc1 $f11, THREAD_FPR11(\thread)
- sdc1 $f13, THREAD_FPR13(\thread)
- sdc1 $f15, THREAD_FPR15(\thread)
- sdc1 $f17, THREAD_FPR17(\thread)
- sdc1 $f19, THREAD_FPR19(\thread)
- sdc1 $f21, THREAD_FPR21(\thread)
- sdc1 $f23, THREAD_FPR23(\thread)
- sdc1 $f25, THREAD_FPR25(\thread)
- sdc1 $f27, THREAD_FPR27(\thread)
- sdc1 $f29, THREAD_FPR29(\thread)
- sdc1 $f31, THREAD_FPR31(\thread)
- .endm
-
- .macro fpu_save_double thread status tmp
- sll \tmp, \status, 5
- bgez \tmp, 2f
- fpu_save_16odd \thread
-2:
- fpu_save_16even \thread \tmp
- .endm
-
- .macro fpu_restore_16even thread tmp=t0
- lw \tmp, THREAD_FCR31(\thread)
- ldc1 $f0, THREAD_FPR0(\thread)
- ldc1 $f2, THREAD_FPR2(\thread)
- ldc1 $f4, THREAD_FPR4(\thread)
- ldc1 $f6, THREAD_FPR6(\thread)
- ldc1 $f8, THREAD_FPR8(\thread)
- ldc1 $f10, THREAD_FPR10(\thread)
- ldc1 $f12, THREAD_FPR12(\thread)
- ldc1 $f14, THREAD_FPR14(\thread)
- ldc1 $f16, THREAD_FPR16(\thread)
- ldc1 $f18, THREAD_FPR18(\thread)
- ldc1 $f20, THREAD_FPR20(\thread)
- ldc1 $f22, THREAD_FPR22(\thread)
- ldc1 $f24, THREAD_FPR24(\thread)
- ldc1 $f26, THREAD_FPR26(\thread)
- ldc1 $f28, THREAD_FPR28(\thread)
- ldc1 $f30, THREAD_FPR30(\thread)
- ctc1 \tmp, fcr31
- .endm
-
- .macro fpu_restore_16odd thread
- ldc1 $f1, THREAD_FPR1(\thread)
- ldc1 $f3, THREAD_FPR3(\thread)
- ldc1 $f5, THREAD_FPR5(\thread)
- ldc1 $f7, THREAD_FPR7(\thread)
- ldc1 $f9, THREAD_FPR9(\thread)
- ldc1 $f11, THREAD_FPR11(\thread)
- ldc1 $f13, THREAD_FPR13(\thread)
- ldc1 $f15, THREAD_FPR15(\thread)
- ldc1 $f17, THREAD_FPR17(\thread)
- ldc1 $f19, THREAD_FPR19(\thread)
- ldc1 $f21, THREAD_FPR21(\thread)
- ldc1 $f23, THREAD_FPR23(\thread)
- ldc1 $f25, THREAD_FPR25(\thread)
- ldc1 $f27, THREAD_FPR27(\thread)
- ldc1 $f29, THREAD_FPR29(\thread)
- ldc1 $f31, THREAD_FPR31(\thread)
- .endm
-
- .macro fpu_restore_double thread status tmp
- sll \tmp, \status, 5
- bgez \tmp, 1f # 16 register mode?
-
- fpu_restore_16odd \thread
-1: fpu_restore_16even \thread \tmp
- .endm
-
.macro cpu_save_nonscratch thread
LONG_S s0, THREAD_REG16(\thread)
LONG_S s1, THREAD_REG17(\thread)
diff --git a/arch/mips/include/asm/asmmacro.h b/arch/mips/include/asm/asmmacro.h
index 6c8342a..3220c93 100644
--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -62,6 +62,113 @@
.endm
#endif /* CONFIG_MIPS_MT_SMTC */
+ .macro fpu_save_16even thread tmp=t0
+ cfc1 \tmp, fcr31
+ sdc1 $f0, THREAD_FPR0(\thread)
+ sdc1 $f2, THREAD_FPR2(\thread)
+ sdc1 $f4, THREAD_FPR4(\thread)
+ sdc1 $f6, THREAD_FPR6(\thread)
+ sdc1 $f8, THREAD_FPR8(\thread)
+ sdc1 $f10, THREAD_FPR10(\thread)
+ sdc1 $f12, THREAD_FPR12(\thread)
+ sdc1 $f14, THREAD_FPR14(\thread)
+ sdc1 $f16, THREAD_FPR16(\thread)
+ sdc1 $f18, THREAD_FPR18(\thread)
+ sdc1 $f20, THREAD_FPR20(\thread)
+ sdc1 $f22, THREAD_FPR22(\thread)
+ sdc1 $f24, THREAD_FPR24(\thread)
+ sdc1 $f26, THREAD_FPR26(\thread)
+ sdc1 $f28, THREAD_FPR28(\thread)
+ sdc1 $f30, THREAD_FPR30(\thread)
+ sw \tmp, THREAD_FCR31(\thread)
+ .endm
+
+ .macro fpu_save_16odd thread
+ .set push
+ .set mips64r2
+ sdc1 $f1, THREAD_FPR1(\thread)
+ sdc1 $f3, THREAD_FPR3(\thread)
+ sdc1 $f5, THREAD_FPR5(\thread)
+ sdc1 $f7, THREAD_FPR7(\thread)
+ sdc1 $f9, THREAD_FPR9(\thread)
+ sdc1 $f11, THREAD_FPR11(\thread)
+ sdc1 $f13, THREAD_FPR13(\thread)
+ sdc1 $f15, THREAD_FPR15(\thread)
+ sdc1 $f17, THREAD_FPR17(\thread)
+ sdc1 $f19, THREAD_FPR19(\thread)
+ sdc1 $f21, THREAD_FPR21(\thread)
+ sdc1 $f23, THREAD_FPR23(\thread)
+ sdc1 $f25, THREAD_FPR25(\thread)
+ sdc1 $f27, THREAD_FPR27(\thread)
+ sdc1 $f29, THREAD_FPR29(\thread)
+ sdc1 $f31, THREAD_FPR31(\thread)
+ .set pop
+ .endm
+
+ .macro fpu_save_double thread status tmp
+#if defined(CONFIG_MIPS64) || defined(CONFIG_CPU_MIPS32_R2)
+ sll \tmp, \status, 5
+ bgez \tmp, 10f
+ fpu_save_16odd \thread
+10:
+#endif
+ fpu_save_16even \thread \tmp
+ .endm
+
+ .macro fpu_restore_16even thread tmp=t0
+ lw \tmp, THREAD_FCR31(\thread)
+ ldc1 $f0, THREAD_FPR0(\thread)
+ ldc1 $f2, THREAD_FPR2(\thread)
+ ldc1 $f4, THREAD_FPR4(\thread)
+ ldc1 $f6, THREAD_FPR6(\thread)
+ ldc1 $f8, THREAD_FPR8(\thread)
+ ldc1 $f10, THREAD_FPR10(\thread)
+ ldc1 $f12, THREAD_FPR12(\thread)
+ ldc1 $f14, THREAD_FPR14(\thread)
+ ldc1 $f16, THREAD_FPR16(\thread)
+ ldc1 $f18, THREAD_FPR18(\thread)
+ ldc1 $f20, THREAD_FPR20(\thread)
+ ldc1 $f22, THREAD_FPR22(\thread)
+ ldc1 $f24, THREAD_FPR24(\thread)
+ ldc1 $f26, THREAD_FPR26(\thread)
+ ldc1 $f28, THREAD_FPR28(\thread)
+ ldc1 $f30, THREAD_FPR30(\thread)
+ ctc1 \tmp, fcr31
+ .endm
+
+ .macro fpu_restore_16odd thread
+ .set push
+ .set mips64r2
+ ldc1 $f1, THREAD_FPR1(\thread)
+ ldc1 $f3, THREAD_FPR3(\thread)
+ ldc1 $f5, THREAD_FPR5(\thread)
+ ldc1 $f7, THREAD_FPR7(\thread)
+ ldc1 $f9, THREAD_FPR9(\thread)
+ ldc1 $f11, THREAD_FPR11(\thread)
+ ldc1 $f13, THREAD_FPR13(\thread)
+ ldc1 $f15, THREAD_FPR15(\thread)
+ ldc1 $f17, THREAD_FPR17(\thread)
+ ldc1 $f19, THREAD_FPR19(\thread)
+ ldc1 $f21, THREAD_FPR21(\thread)
+ ldc1 $f23, THREAD_FPR23(\thread)
+ ldc1 $f25, THREAD_FPR25(\thread)
+ ldc1 $f27, THREAD_FPR27(\thread)
+ ldc1 $f29, THREAD_FPR29(\thread)
+ ldc1 $f31, THREAD_FPR31(\thread)
+ .set pop
+ .endm
+
+ .macro fpu_restore_double thread status tmp
+#if defined(CONFIG_MIPS64) || defined(CONFIG_CPU_MIPS32_R2)
+ sll \tmp, \status, 5
+ bgez \tmp, 10f # 16 register mode?
+
+ fpu_restore_16odd \thread
+10:
+#endif
+ fpu_restore_16even \thread \tmp
+ .endm
+
/*
* Temporary until all gas have MT ASE support
*/
diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index a66359e..17163cf 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -36,6 +36,7 @@
#define EF_MIPS_ABI2 0x00000020
#define EF_MIPS_OPTIONS_FIRST 0x00000080
#define EF_MIPS_32BITMODE 0x00000100
+#define EF_MIPS_FP64 0x00000200
#define EF_MIPS_ABI 0x0000f000
#define EF_MIPS_ARCH 0xf0000000
@@ -249,6 +250,11 @@ extern struct mips_abi mips_abi_n32;
#define SET_PERSONALITY(ex) \
do { \
+ if ((ex).e_flags & EF_MIPS_FP64) \
+ clear_thread_flag(TIF_32BIT_FPREGS); \
+ else \
+ set_thread_flag(TIF_32BIT_FPREGS); \
+ \
if (personality(current->personality) != PER_LINUX) \
set_personality(PER_LINUX); \
\
@@ -271,14 +277,18 @@ do { \
#endif
#ifdef CONFIG_MIPS32_O32
-#define __SET_PERSONALITY32_O32() \
+#define __SET_PERSONALITY32_O32(ex) \
do { \
set_thread_flag(TIF_32BIT_REGS); \
set_thread_flag(TIF_32BIT_ADDR); \
+ \
+ if (!((ex).e_flags & EF_MIPS_FP64)) \
+ set_thread_flag(TIF_32BIT_FPREGS); \
+ \
current->thread.abi = &mips_abi_32; \
} while (0)
#else
-#define __SET_PERSONALITY32_O32() \
+#define __SET_PERSONALITY32_O32(ex) \
do { } while (0)
#endif
@@ -289,7 +299,7 @@ do { \
((ex).e_flags & EF_MIPS_ABI) == 0) \
__SET_PERSONALITY32_N32(); \
else \
- __SET_PERSONALITY32_O32(); \
+ __SET_PERSONALITY32_O32(ex); \
} while (0)
#else
#define __SET_PERSONALITY32(ex) do { } while (0)
@@ -300,6 +310,7 @@ do { \
unsigned int p; \
\
clear_thread_flag(TIF_32BIT_REGS); \
+ clear_thread_flag(TIF_32BIT_FPREGS); \
clear_thread_flag(TIF_32BIT_ADDR); \
\
if ((ex).e_ident[EI_CLASS] == ELFCLASS32) \
diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h
index 3bf023f..cfe092f 100644
--- a/arch/mips/include/asm/fpu.h
+++ b/arch/mips/include/asm/fpu.h
@@ -33,11 +33,48 @@ extern void _init_fpu(void);
extern void _save_fp(struct task_struct *);
extern void _restore_fp(struct task_struct *);
-#define __enable_fpu() \
-do { \
- set_c0_status(ST0_CU1); \
- enable_fpu_hazard(); \
-} while (0)
+/*
+ * This enum specifies a mode in which we want the FPU to operate, for cores
+ * which implement the Status.FR bit. Note that FPU_32BIT & FPU_64BIT
+ * purposefully have the values 0 & 1 respectively, so that an integer value
+ * of Status.FR can be trivially casted to the corresponding enum fpu_mode.
+ */
+enum fpu_mode {
+ FPU_32BIT = 0, /* FR = 0 */
+ FPU_64BIT, /* FR = 1 */
+ FPU_AS_IS,
+};
+
+static inline int __enable_fpu(enum fpu_mode mode)
+{
+ int fr;
+
+ switch (mode) {
+ case FPU_AS_IS:
+ /* just enable the FPU in its current mode */
+ set_c0_status(ST0_CU1);
+ enable_fpu_hazard();
+ return 0;
+
+ case FPU_64BIT:
+#if !(defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_MIPS64))
+ /* we only have a 32-bit FPU */
+ return SIGFPE;
+#endif
+ /* fall through */
+ case FPU_32BIT:
+ /* set CU1 & change FR appropriately */
+ fr = (int)mode;
+ change_c0_status(ST0_CU1 | ST0_FR, ST0_CU1 | (fr ? ST0_FR : 0));
+ enable_fpu_hazard();
+
+ /* check FR has the desired value */
+ return (!!(read_c0_status() & ST0_FR) == !!fr) ? 0 : SIGFPE;
+
+ default:
+ BUG();
+ }
+}
#define __disable_fpu() \
do { \
@@ -57,27 +94,46 @@ static inline int is_fpu_owner(void)
return cpu_has_fpu && __is_fpu_owner();
}
-static inline void __own_fpu(void)
+static inline int __own_fpu(void)
{
- __enable_fpu();
+ enum fpu_mode mode;
+ int ret;
+
+ mode = !test_thread_flag(TIF_32BIT_FPREGS);
+ ret = __enable_fpu(mode);
+ if (ret)
+ return ret;
+
KSTK_STATUS(current) |= ST0_CU1;
+ if (mode == FPU_64BIT)
+ KSTK_STATUS(current) |= ST0_FR;
+ else /* mode == FPU_32BIT */
+ KSTK_STATUS(current) &= ~ST0_FR;
+
set_thread_flag(TIF_USEDFPU);
+ return 0;
}
-static inline void own_fpu_inatomic(int restore)
+static inline int own_fpu_inatomic(int restore)
{
+ int ret = 0;
+
if (cpu_has_fpu && !__is_fpu_owner()) {
- __own_fpu();
- if (restore)
+ ret = __own_fpu();
+ if (restore && !ret)
_restore_fp(current);
}
+ return ret;
}
-static inline void own_fpu(int restore)
+static inline int own_fpu(int restore)
{
+ int ret;
+
preempt_disable();
- own_fpu_inatomic(restore);
+ ret = own_fpu_inatomic(restore);
preempt_enable();
+ return ret;
}
static inline void lose_fpu(int save)
@@ -93,16 +149,21 @@ static inline void lose_fpu(int save)
preempt_enable();
}
-static inline void init_fpu(void)
+static inline int init_fpu(void)
{
+ int ret = 0;
+
preempt_disable();
if (cpu_has_fpu) {
- __own_fpu();
- _init_fpu();
+ ret = __own_fpu();
+ if (!ret)
+ _init_fpu();
} else {
fpu_emulator_init_fpu();
}
+
preempt_enable();
+ return ret;
}
static inline void save_fp(struct task_struct *tsk)
diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index f9b24bf..b6da8b7 100644
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -112,11 +112,12 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_NOHZ 19 /* in adaptive nohz mode */
#define TIF_FIXADE 20 /* Fix address errors in software */
#define TIF_LOGADE 21 /* Log address errors to syslog */
-#define TIF_32BIT_REGS 22 /* also implies 16/32 fprs */
+#define TIF_32BIT_REGS 22 /* 32-bit general purpose registers */
#define TIF_32BIT_ADDR 23 /* 32-bit address space (o32/n32) */
#define TIF_FPUBOUND 24 /* thread bound to FPU-full CPU set */
#define TIF_LOAD_WATCH 25 /* If set, load watch registers */
#define TIF_SYSCALL_TRACEPOINT 26 /* syscall tracepoint instrumentation */
+#define TIF_32BIT_FPREGS 27 /* 32-bit floating point registers */
#define TIF_SYSCALL_TRACE 31 /* syscall trace active */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@@ -133,6 +134,7 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_32BIT_ADDR (1<<TIF_32BIT_ADDR)
#define _TIF_FPUBOUND (1<<TIF_FPUBOUND)
#define _TIF_LOAD_WATCH (1<<TIF_LOAD_WATCH)
+#define _TIF_32BIT_FPREGS (1<<TIF_32BIT_FPREGS)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_WORK_SYSCALL_ENTRY (_TIF_NOHZ | _TIF_SYSCALL_TRACE | \
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 8168e29..116102c 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -112,7 +112,7 @@ static inline unsigned long cpu_get_fpu_id(void)
unsigned long tmp, fpu_id;
tmp = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
fpu_id = read_32bit_cp1_register(CP1_REVISION);
write_c0_status(tmp);
return fpu_id;
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index ddc7610..747a6cf 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -60,9 +60,6 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
/* New thread loses kernel privileges. */
status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK);
-#ifdef CONFIG_64BIT
- status |= test_thread_flag(TIF_32BIT_REGS) ? 0 : ST0_FR;
-#endif
status |= KU_USER;
regs->cp0_status = status;
clear_used_math();
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index b52e1d2..30b1a43 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -137,13 +137,13 @@ int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
write_c0_status(flags);
}
@@ -483,13 +483,13 @@ long arch_ptrace(struct task_struct *child, long request,
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
}
diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c
index 9486055..020342a 100644
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -147,13 +147,13 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
- __enable_fpu();
+ __enable_fpu(FPU_AS_IS);
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
}
diff --git a/arch/mips/kernel/r4k_fpu.S b/arch/mips/kernel/r4k_fpu.S
index 55ffe14..253b2fb 100644
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -35,7 +35,15 @@
LEAF(_save_fp_context)
cfc1 t1, fcr31
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) || defined(CONFIG_MIPS32_R2)
+ .set push
+#ifdef CONFIG_MIPS32_R2
+ .set mips64r2
+ mfc0 t0, CP0_STATUS
+ sll t0, t0, 5
+ bgez t0, 1f # skip storing odd if FR=0
+ nop
+#endif
/* Store the 16 odd double precision registers */
EX sdc1 $f1, SC_FPREGS+8(a0)
EX sdc1 $f3, SC_FPREGS+24(a0)
@@ -53,6 +61,7 @@ LEAF(_save_fp_context)
EX sdc1 $f27, SC_FPREGS+216(a0)
EX sdc1 $f29, SC_FPREGS+232(a0)
EX sdc1 $f31, SC_FPREGS+248(a0)
+1: .set pop
#endif
/* Store the 16 even double precision registers */
@@ -82,7 +91,31 @@ LEAF(_save_fp_context)
LEAF(_save_fp_context32)
cfc1 t1, fcr31
- EX sdc1 $f0, SC32_FPREGS+0(a0)
+ mfc0 t0, CP0_STATUS
+ sll t0, t0, 5
+ bgez t0, 1f # skip storing odd if FR=0
+ nop
+
+ /* Store the 16 odd double precision registers */
+ EX sdc1 $f1, SC32_FPREGS+8(a0)
+ EX sdc1 $f3, SC32_FPREGS+24(a0)
+ EX sdc1 $f5, SC32_FPREGS+40(a0)
+ EX sdc1 $f7, SC32_FPREGS+56(a0)
+ EX sdc1 $f9, SC32_FPREGS+72(a0)
+ EX sdc1 $f11, SC32_FPREGS+88(a0)
+ EX sdc1 $f13, SC32_FPREGS+104(a0)
+ EX sdc1 $f15, SC32_FPREGS+120(a0)
+ EX sdc1 $f17, SC32_FPREGS+136(a0)
+ EX sdc1 $f19, SC32_FPREGS+152(a0)
+ EX sdc1 $f21, SC32_FPREGS+168(a0)
+ EX sdc1 $f23, SC32_FPREGS+184(a0)
+ EX sdc1 $f25, SC32_FPREGS+200(a0)
+ EX sdc1 $f27, SC32_FPREGS+216(a0)
+ EX sdc1 $f29, SC32_FPREGS+232(a0)
+ EX sdc1 $f31, SC32_FPREGS+248(a0)
+
+ /* Store the 16 even double precision registers */
+1: EX sdc1 $f0, SC32_FPREGS+0(a0)
EX sdc1 $f2, SC32_FPREGS+16(a0)
EX sdc1 $f4, SC32_FPREGS+32(a0)
EX sdc1 $f6, SC32_FPREGS+48(a0)
@@ -114,7 +147,16 @@ LEAF(_save_fp_context32)
*/
LEAF(_restore_fp_context)
EX lw t0, SC_FPC_CSR(a0)
-#ifdef CONFIG_64BIT
+
+#if defined(CONFIG_64BIT) || defined(CONFIG_MIPS32_R2)
+ .set push
+#ifdef CONFIG_MIPS32_R2
+ .set mips64r2
+ mfc0 t0, CP0_STATUS
+ sll t0, t0, 5
+ bgez t0, 1f # skip loading odd if FR=0
+ nop
+#endif
EX ldc1 $f1, SC_FPREGS+8(a0)
EX ldc1 $f3, SC_FPREGS+24(a0)
EX ldc1 $f5, SC_FPREGS+40(a0)
@@ -131,6 +173,7 @@ LEAF(_restore_fp_context)
EX ldc1 $f27, SC_FPREGS+216(a0)
EX ldc1 $f29, SC_FPREGS+232(a0)
EX ldc1 $f31, SC_FPREGS+248(a0)
+1: .set pop
#endif
EX ldc1 $f0, SC_FPREGS+0(a0)
EX ldc1 $f2, SC_FPREGS+16(a0)
@@ -157,7 +200,30 @@ LEAF(_restore_fp_context)
LEAF(_restore_fp_context32)
/* Restore an o32 sigcontext. */
EX lw t0, SC32_FPC_CSR(a0)
- EX ldc1 $f0, SC32_FPREGS+0(a0)
+
+ mfc0 t0, CP0_STATUS
+ sll t0, t0, 5
+ bgez t0, 1f # skip loading odd if FR=0
+ nop
+
+ EX ldc1 $f1, SC32_FPREGS+8(a0)
+ EX ldc1 $f3, SC32_FPREGS+24(a0)
+ EX ldc1 $f5, SC32_FPREGS+40(a0)
+ EX ldc1 $f7, SC32_FPREGS+56(a0)
+ EX ldc1 $f9, SC32_FPREGS+72(a0)
+ EX ldc1 $f11, SC32_FPREGS+88(a0)
+ EX ldc1 $f13, SC32_FPREGS+104(a0)
+ EX ldc1 $f15, SC32_FPREGS+120(a0)
+ EX ldc1 $f17, SC32_FPREGS+136(a0)
+ EX ldc1 $f19, SC32_FPREGS+152(a0)
+ EX ldc1 $f21, SC32_FPREGS+168(a0)
+ EX ldc1 $f23, SC32_FPREGS+184(a0)
+ EX ldc1 $f25, SC32_FPREGS+200(a0)
+ EX ldc1 $f27, SC32_FPREGS+216(a0)
+ EX ldc1 $f29, SC32_FPREGS+232(a0)
+ EX ldc1 $f31, SC32_FPREGS+248(a0)
+
+1: EX ldc1 $f0, SC32_FPREGS+0(a0)
EX ldc1 $f2, SC32_FPREGS+16(a0)
EX ldc1 $f4, SC32_FPREGS+32(a0)
EX ldc1 $f6, SC32_FPREGS+48(a0)
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index 078de5e..cc78dd9 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -123,7 +123,7 @@
* Save a thread's fp context.
*/
LEAF(_save_fp)
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
mfc0 t0, CP0_STATUS
#endif
fpu_save_double a0 t0 t1 # clobbers t1
@@ -134,7 +134,7 @@ LEAF(_save_fp)
* Restore a thread's fp context.
*/
LEAF(_restore_fp)
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2)
mfc0 t0, CP0_STATUS
#endif
fpu_restore_double a0 t0 t1 # clobbers t1
@@ -228,6 +228,47 @@ LEAF(_init_fpu)
mtc1 t1, $f29
mtc1 t1, $f30
mtc1 t1, $f31
+
+#ifdef CONFIG_CPU_MIPS32_R2
+ .set push
+ .set mips64r2
+ sll t0, t0, 5 # is Status.FR set?
+ bgez t0, 1f # no: skip setting upper 32b
+
+ mthc1 t1, $f0
+ mthc1 t1, $f1
+ mthc1 t1, $f2
+ mthc1 t1, $f3
+ mthc1 t1, $f4
+ mthc1 t1, $f5
+ mthc1 t1, $f6
+ mthc1 t1, $f7
+ mthc1 t1, $f8
+ mthc1 t1, $f9
+ mthc1 t1, $f10
+ mthc1 t1, $f11
+ mthc1 t1, $f12
+ mthc1 t1, $f13
+ mthc1 t1, $f14
+ mthc1 t1, $f15
+ mthc1 t1, $f16
+ mthc1 t1, $f17
+ mthc1 t1, $f18
+ mthc1 t1, $f19
+ mthc1 t1, $f20
+ mthc1 t1, $f21
+ mthc1 t1, $f22
+ mthc1 t1, $f23
+ mthc1 t1, $f24
+ mthc1 t1, $f25
+ mthc1 t1, $f26
+ mthc1 t1, $f27
+ mthc1 t1, $f28
+ mthc1 t1, $f29
+ mthc1 t1, $f30
+ mthc1 t1, $f31
+1: .set pop
+#endif /* CONFIG_CPU_MIPS32_R2 */
#else
.set mips3
dmtc1 t1, $f0
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2f285ab..5199563 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -71,8 +71,9 @@ static int protected_save_fp_context(struct sigcontext __user *sc)
int err;
while (1) {
lock_fpu_owner();
- own_fpu_inatomic(1);
- err = save_fp_context(sc); /* this might fail */
+ err = own_fpu_inatomic(1);
+ if (!err)
+ err = save_fp_context(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
@@ -91,8 +92,9 @@ static int protected_restore_fp_context(struct sigcontext __user *sc)
int err, tmp __maybe_unused;
while (1) {
lock_fpu_owner();
- own_fpu_inatomic(0);
- err = restore_fp_context(sc); /* this might fail */
+ err = own_fpu_inatomic(0);
+ if (!err)
+ err = restore_fp_context(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index 57de8b7..7c1024b 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -85,8 +85,9 @@ static int protected_save_fp_context32(struct sigcontext32 __user *sc)
int err;
while (1) {
lock_fpu_owner();
- own_fpu_inatomic(1);
- err = save_fp_context32(sc); /* this might fail */
+ err = own_fpu_inatomic(1);
+ if (!err)
+ err = save_fp_context32(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
@@ -105,8 +106,9 @@ static int protected_restore_fp_context32(struct sigcontext32 __user *sc)
int err, tmp __maybe_unused;
while (1) {
lock_fpu_owner();
- own_fpu_inatomic(0);
- err = restore_fp_context32(sc); /* this might fail */
+ err = own_fpu_inatomic(0);
+ if (!err)
+ err = restore_fp_context32(sc); /* this might fail */
unlock_fpu_owner();
if (likely(!err))
break;
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index cc20415..eb28423 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1080,7 +1080,7 @@ asmlinkage void do_cpu(struct pt_regs *regs)
unsigned long old_epc, old31;
unsigned int opcode;
unsigned int cpid;
- int status;
+ int status, err;
unsigned long __maybe_unused flags;
prev_state = exception_enter();
@@ -1153,19 +1153,29 @@ asmlinkage void do_cpu(struct pt_regs *regs)
case 1:
if (used_math()) /* Using the FPU again. */
- own_fpu(1);
+ err = own_fpu(1);
else { /* First time FPU user. */
- init_fpu();
+ err = init_fpu();
set_used_math();
}
- if (!raw_cpu_has_fpu) {
+#ifndef CONFIG_MIPS_O32_FP64_SUPPORT
+ /*
+ * This assumes that either all FPUs in the system support
+ * Status.FR (ie. both 32-bit & 64-bit) or none of them do.
+ */
+ if (err) {
+ force_sig(SIGFPE, current);
+ goto out;
+ }
+#endif
+ if (!raw_cpu_has_fpu || err) {
int sig;
void __user *fault_addr = NULL;
sig = fpu_emulator_cop1Handler(regs,
¤t->thread.fpu,
0, &fault_addr);
- if (!process_fpemu_return(sig, fault_addr))
+ if (!process_fpemu_return(sig, fault_addr) && !err)
mt_ase_fp_affinity();
}
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 4b37961..22f7b11 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -859,20 +859,20 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
* In the Linux kernel, we support selection of FPR format on the
* basis of the Status.FR bit. If an FPU is not present, the FR bit
* is hardwired to zero, which would imply a 32-bit FPU even for
- * 64-bit CPUs so we rather look at TIF_32BIT_REGS.
+ * 64-bit CPUs so we rather look at TIF_32BIT_FPREGS.
* FPU emu is slow and bulky and optimizing this function offers fairly
* sizeable benefits so we try to be clever and make this function return
* a constant whenever possible, that is on 64-bit kernels without O32
- * compatibility enabled and on 32-bit kernels.
+ * compatibility enabled and on 32-bit without 64-bit FPU support.
*/
static inline int cop1_64bit(struct pt_regs *xcp)
{
#if defined(CONFIG_64BIT) && !defined(CONFIG_MIPS32_O32)
return 1;
-#elif defined(CONFIG_64BIT) && defined(CONFIG_MIPS32_O32)
- return !test_thread_flag(TIF_32BIT_REGS);
-#else
+#elif defined(CONFIG_32BIT) && !defined(CONFIG_MIPS_O32_FP64_SUPPORT)
return 0;
+#else
+ return !test_thread_flag(TIF_32BIT_FPREGS);
#endif
}
diff --git a/arch/mips/math-emu/kernel_linkage.c b/arch/mips/math-emu/kernel_linkage.c
index 1c58657..3aeae07 100644
--- a/arch/mips/math-emu/kernel_linkage.c
+++ b/arch/mips/math-emu/kernel_linkage.c
@@ -89,8 +89,9 @@ int fpu_emulator_save_context32(struct sigcontext32 __user *sc)
{
int i;
int err = 0;
+ int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
- for (i = 0; i < 32; i+=2) {
+ for (i = 0; i < 32; i += inc) {
err |=
__put_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
}
@@ -103,8 +104,9 @@ int fpu_emulator_restore_context32(struct sigcontext32 __user *sc)
{
int i;
int err = 0;
+ int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
- for (i = 0; i < 32; i+=2) {
+ for (i = 0; i < 32; i += inc) {
err |=
__get_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
}
--
1.8.4.1
